Foam plastic printing block and method of etching same



Oct. 5, 1965 P. M. ARTHURS 3,209,686

FOAM PLASTIC PRINTING BLOCK AND METHOD OF ETCHING SAME Filed April 8, 1964 FIGZ INVENTOR. fizz/hie Aral/r: BY

A TTORNE Y United States Patent 3,209,686 FOAM PLASTIC PRINTING BLOCK AND METHOD OF ETCHING SAME Pauline M. Arthurs, Salisbury, N.C., assignor to Star Band Company, Inc., Portsmouth, Va. Filed Apr. 8, 1964, Ser. No. 358,312 2 Claims. (Cl. 101368) The present invention relates to block printing, and more particularly is directed to the use of rigid blocks of expanded or foamed plastic materials in block printing, and a novel method of preparing the blocks for the printing function.

The broad concept of etching or covering a negative pattern into the surface of a block or plate, inking the surface, and applying the block to an image-receiving surface whereby the recovery surface is left with an ink impression over all areas except where the pattern was cut into the block is well-known in the art of printing and ornamenting. It is the purpose of this invention to provide an improved block printing means that can make such printing available for entertainment, educational and everyday decorative purposes, to persons of all ages and maturity, particularly children.

While practically any material in which a pattern can be etched, cut, stamped, etc., could conceivably be used in block printing, it is apparent that in order to make such apparatus available to youngsters or to people of any age at a very low cost and with the utmost of safety and convenience, particular materials and particular methods of using the materials become of prime importance. It would be highly desirable to have available a block material that is very lightweight, dimensionally stable, substantially rigid when unsupported by another material, very inexpensive, receptive to inks, and in particular, having physical characteristics which lend themselves to the negative relief pattern forming operation. This last qualification, namely, ease of pattern forming on the surface of a printing block, is of prime importance when it is desired to produce a printing block kit that will appeal to the widest possible range of people. Such a kit should appeal to educators as truly a fine method for introducing youngsters to the graphic arts; to hobbyists as an entertaining and creative method of expression; to any and all individuals who seek a simple way to transfer an image, artisitic or otherwise, that they themselves have created onto .a suitable surface, such as paper or cloth. On the other hand, if the block printing materials involve dangerous instrumentalities such as sharp cutting tools and strong etching solutions, the field of interest in such apparatus is necessarily narrowed to those individuals who are responsible and mature enough to handle the materials with the needed caution.

Accordingly, it is a primary object of this invention to provide block printing material that fulfills all the requirements outlined above as being desirabde in materials used in such printing processes, while still lending itself to be prepared for printing by means of a relatively harmless solvent.

It is another object of this invention to provide block printing material and a method of preparing same for printing which is ideally suitable for mass marketing techniques in that the materials of the block itself, the pattern forming solution, and the inks that may be used, are

3,209,686 Patented Oct. 5, 1965 with substantially the same degree of freedom of ex pression being preserved. V

Another object of this invention is to provide a printing block formed from rigid sheets of expanded or foamed plastic material into which a pattern may be etched by means of a suitable, relatively harmless, organic solvent which dissolves the plastic in desired locale and areas when it is applied thereto by a suitable drawing tool.

FIG. 1 is a perspective view of a partially etched foam plastic printing block of this invention;

FIG. 2 is a sectional view taken along line 22 of FIG. 1;

FIG. 3 is a perspective view of an etched foam plastic printing block being inked; and

FIG. 4 shows a sheet printed by means of the printing block shown in FIG. 1.

Referring now to the drawings and in particular to FIG, 1, a printing block 10 is shown with a partially etched negative relief pattern 12, 12' in the surface thereof. The block 10 may be of any dimension, but is shown rectangular in form here by way of example. The block 10 is a rigid sheet of expanded or foam plastic material, preferably polystyrene foam, but alternately may be formed of polyurethane, polyvinyl chloride, cellulose acetate, or similar plastic material in foamed, rigid condition.v

The pattern 12 being created is formed in this instance by means of a drawing tool 14 having a felt nib 16 on its tip portion in contact with the foam block 10. The drawing tool 14 contains a-supply of a suitable liquid solvent material which is fed to the nib by wick action. When the nib is placed in contact with the foam block 10, the solvent dissolves in a localized portion of the plastic material of the block 10, in the immediate vicinity of the nib 16. As the drawing tool is manipulated over the plastic block, the dissolving action is continuous along the path of travel of the nib. The depth of etch may be regulated by the strength of the solvent used, by the speed at which the tool 14 traverses the surface of the block 10, by the pressure applied to the tool 14, and even by the rate of flow of solvent from the nib 16. The lateral dimensions of the etch pattern may be controlled most conveninetly by choice of nib size, a choice of nib sizes or drawing tools with various nib sizes being usually available.

As shown in FIG. 2, the etched pattern 12 or 12' illustrates various depths of etching that may be produced in the foam block. Of course, it is to be understood that the particular embodiment of drawing tool 14 shown is illustrative only and in actual practice any instrument for controllably applying solvent to a localized area of the plastic block may be used. Needless to say the particular drawing instrument used is quite incidental and may be any instrument selected by a person that will produce a desired etch pattern or characteristic.

The ability of certain plastic compositions to be readily etched by means of relatively harmless organic solvents is utilized in this invention to provide a printing block forming system having the evident range of appeal. Thus, with the foamed plastics set forth above, it is contemplated to use highly volatile organic solvents for these plastics as the etching medium. Such solvents may be any one or a combination of the following, depending upon the plastic foam to be etched, the relative safety desired, and the speed of etching contemplated. All the solvents listed hereinafter serve as quickly evaporating etching liquids: ketones such as acetone, methylethyl ketone, methylisobutyl ketone, etc.; alcohols such as ethyl alcohol, isobutyl alcohol, isopropyl alcohol, n-butyl alcohol; hydrocarbons such as benzene, xylene, toluene, petroleum ether, etc.; chlorinated hydrocarbons such as ethylene dichloride, carbon tetrachloride, methylene chloride, dichlorodifiuoromethane (Freon type); esters such as ethyl acetate, methyl acetate, butyl acetate, methylbutyrate and the like. The combinations of these solvents in proportions which are designed to rely upon the combined solvent etching effects can serve to regulate the depth of etching and thereby facilitate very fine shading. Virtually any known volatile harmless solvent for plastic can be used.

The term harmless herein used does not denote an absolute lack of any danger to persons or articles that are exposed but does indicate that these solvents will readily evaporate but will not be taken internally. Compared with sharp knives and cutters used in linoleum or wood printing block making, and with caustic on acid etchants that have been used, the organic solvents used according to the process of this invention will be found relatively harmless, and require less supervision in their use than the other materials. It becomes possible by means of the foam block and organic solvent to allow young children to form patterns in plastic block material provided them and then to print the reverse image on paper or other material that seems most appropriate or desirable. The use of a simple, pen-like drawing tool reduces most risks that would otherwise be involved due to certain properties of the solvents used, and furthermore the simple penlike form of instrument used as the pattern etching tool is familiar to children and does not require the use of skills not already learned. The simple process of locally dissolving portions of the plastic block furthermore permit the widest range of artistic expression with a minimum of restraint imposed by mechanical limitations of the pattern forming process. Virtually anything that can be drawn can be etched into the foamed plastic blocks. The blocks themselves are extremely light weight and easily manipulated by young children or others utilizing the apparatus.

In use the etched foamed block is inked in any desirable color in a conventional manner as shown in FIGURE 3, using an ink impregnated brayer, or printers inker 18. Any conventional letter press ink or water base ink may be used, these consisting essentially of pigment, either organic or inorganic pigment dispersed in a liquid medium which sets to a rub-resistant finish. In letter press ink the liquid medium may be vegetable oil, linseed oil thinned with turpentine solvent for mixing with pigment and bodied with ester gum, wax gilsonite, rosin, or cumarone-indene resin. In water base ink the liquid vehicle water may be thickened with starch, vegetable gum, modified with glycerine or polyhydric alcohols and blended with wetting agents.

Organic pigments usable are:

Lithol red Hansa yellow Carbon black or lamp black Toluidine maroon Nigrosine Iudanthrene blue Phthalocyanine blue Van Dyke brown Phthalocyanine green Amaranth Inorganic pigments usable are:

American vermillion Ultramarine blue Cadmium red Chromium oxide Chrome yellow Iron blue Red lead Iron oxide Gold leaf Aluminum black Copper bronze Yellow ochre Sienna Umber The shaded portion 20 in FIGURE 3 represents the inked portion of the block 10. It will be obvious that the unetched surface portion of the block 10 receives the ink material while the etched portion thereof remains open and free of ink. It is contemplated that water soluble inks would be used where childrens projects are involved to minimize cleanup problems, and to allow the foam printing block 10 to be cleaned and stored for later re-use.

Once the block 10 has been inked the block itself may be applied to the image surface or a suitable sheet 23 of material to be printed may be placed upon the etched surface of the foam block. In either event the result is the same, and, as illustrated in FIG. 4, the ink covers the printed surface save those areas that have been etched, leaving a print 22 of any desired configuration. In FIG- URE 4, for example, the resultant sheet 23 may have been originally black in color with white ink applied to the printing block 10 so that the black pattern 22 was left on the sheet 23.

Any of a variety of effects may be obtained, by varying the color of the inks used, the basic nature and color of the sheet material 23 used, the surface texture of the foamed block 10, the manner of etching the pattern 12, 12, the manner of applying the ink to the block 10, and so forth. However, it is the basic utter simplicity of etching foam plastic printing block material with a suitable organic solvent to obtain a desired pattern that constitutes the crux of the present invention, as well as the added benefits that result from the use of inexpensive, lightweight foam sheets that are receptive to inks and easily etched by solvents. The value of such an arrangement to educators is self evident, as is the basic universal appeal of the system. It is contemplated that kits can be marketed containing various sizes of foam sheets, with drawing tools, inkers, inks, solvents and print sheets whereby hobbyists, artists, teachers, institutions and others desiring to obtain a simple means for printing creative patterns can fulfill their specific needs by purchasing specific kits.

I claim:

1. A method of making a printing member for use in block printing comprising: etching predetermined areas in the roughened surface of a rigid open-pore plastic foam material, selected from the group consisting of foamed polystyrene, foamed cellulose acetate and foamed vinyl chloride polymer, employing a non-toxic highly volatile organic solvent; said solvent being selected from the group consisting of lower aliphatic ketones, lower alcohols, lower aliphatic esters and mixtures of the foregoing with nonharmful quantities of chlorinated hydrocarbons and aromatic hydrocarbons; said etching being carried out by contacting said predetermined areas with an applicator which regulates the depth of etching and thereby facilitates fine. shading effects in printing with said etched block.

2. A block printing member consisting of a rigid openpore plastic foam material having a roughened surface which is etched in predetermined areas, said foam material being selected from the group consisting of foamed polystyrene, foamed cellulose acetate and foamed vinyl chloride polymer, the predetermined etched areas being formed in variable depths based upon the application of a highly volatile non-toxic solvent from an applicator which collapses the cell Walls in the treated areas.

References Cited by the Examiner UNITED STATES PATENTS 1,769,599 7/30 Neidich.

2,358,189 9/44 Sprigg et a1. 101 379 X 2,684,012 7/54 Hebert 101-379X 3,055,297 9/62 Leeds 101395X 3,127,301 3/64 Sigler 101 -395X ROBERT E. PULFREY, Primary Examiner. WILLIAM B. PENN, Examiner. 

1. A METHOD OF MAKING A PRINTING MEMBER FOR USE IN BLOCK PRINTING COMPRISING: ETCHING PREDETERMINED AREAS IN THE ROUGHENED SURFACE OF A RIGID OPEN-PORE PLASTIC FOAM MATERIAL, SELECTED FROM THE GROUP CONSISTING OF FOAMED POLYSTYRENE, FOAMED CELLULOSE ACETATE AND FOAMED VINYL CHLORIDE POLYMER, EMPLOYING A NON-TOXIC HIGHLY VOLATILE ORGANIC SOLVENT; SAID SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF LOWER ALIPHATIC KETONES, LOWER ALOCHOLS, LOWER ALIPHATIC ESTERS AND MIXTURES OF THE FOREGOING WITH NONHARMFUL QUANTITIES OF CHLORINATED HYDROCARBONS AND AROMATIC HYDROCARBONS; SAID ETCHING BEING CARRIED OUT BY CONTACTING SAID PREDETERMINED AREAS WITH AN APPLICATOR WHICH REGULATES THE DEPTH OF ETCHING AND THEREBY FACILITATES FINE SHADING EFFECTS IN PRINTING WITH SAID ETCHED BLOCK. 